Medical devices, such as electrical stimulators, may be used in different therapeutic applications. Medical electrical stimulation devices, for example, may deliver electrical stimulation therapy to a patient via implanted or external electrodes to manage a patient condition. Electrical stimulation therapy may include stimulation of nerve, muscle, or brain tissue, or other tissue within a patient. An electrical stimulation system may be fully implanted within the patient. For example, an electrical stimulation system may include an implantable electrical stimulation generator and one or more implantable leads carrying electrodes. Alternatively, the electrical stimulation device may comprise a leadless stimulator. In some cases, implantable electrodes may be coupled to an external electrical stimulation generator via one or more percutaneous leads or fully implanted leads.
A clinician can select values for a number of programmable stimulation parameters in order to define the electrical stimulation therapy to be delivered to a patient. For example, the clinician may select a current or voltage amplitude of the stimulation, and various characteristics of the stimulation waveform. If the stimulation is delivered in the form of pulses, for example, the clinician may specify a pulse width and pulse rate. In addition, the clinician may specify an electrode configuration used to deliver stimulation, including selected electrode combinations and electrode polarities. A set of parameter values may be referred to as a stimulation program or a therapy program. A program group may include multiple programs. In some cases, therapy can be delivered according to multiple programs in a program group on a simultaneous, time-interleaved, or overlapping basis.